My patent U.S. Pat. No. 4,574,336 and the patent to Domas U.S. Pat. No. 4,387,415 show cornice lighting fixtures that are used in public transit vehicles. They include an elongated display panel for holding advertising cards and an integral lamp housing made in long pieces for mounting longitudinally above the vehicle side windows and over the passenger seats. A translucent cover completes the housing and fluorescent tubes in the housing provide the light source. Inverter ballasts provide the necessary voltage and regulation for the fluorescent lamps. These devices are expensive to install and require maintenance. Thus it is desirable to replace the fluorescent lighting system.
This lighting arrangement supplies sufficient illumination to the region directly below the fixtures to meet governmentally mandated light levels in the seating area and also casts light across the aisle to illuminate the advertising cards on the opposite side of the vehicle. Incidental to this lighting pattern, the fixtures illuminate the aisle floor and side windows as well. The side window illumination is unnecessary and tends to hamper passenger night vision through the window. The lighting of the aisle floor is also unnecessary and tends to reflect onto the vehicle windshield. It is thus expected that both passenger and operator night vision can be enhanced by controlling the light from the fixtures into selected light patterns which significantly reduce the light level incident on the side windows and on the floor of the aisle.
A commercially available optical sheet material has been marketed for use with high intensity incandescent lamps as a substitute for fluorescent tubes. The material is explained in the patents to Whitehead, U.S. Pat. No. 4,260,220 and U.S. Pat. No. 4,615,579. The material is a transparent and reflective sheet and, when fashioned into a tube, serves as a hollow light guide to provide controlled illumination pattern from a lamp provided at its end. It is my proposal to use this material in a different configuration along with incandescent lamps in the lighting fixtures to provide the desired light patterns for a public transit vehicle.